Persell Middle School seventh graders recently learned a bit more about sublimation, which is the process of transition of a substance from the solid phase to the gas phase without passing through an intermediate liquid phase, in Mary Maggio’s science class. Parent Aaron Dunlap, who works for Welder Supply Company, gave a real-life demonstration by bringing in Dry Ice, which is frozen carbon dioxide and liquid nitrogen. By tying the demonstration to their chemistry curriculum, Mr. Dunlap showed how dry ice goes through sublimation. The liquid nitrogen has a boiling point of -321 degrees Fahrenheit. When it was poured out of the canister, it boiled very rapidly and evaporated within minutes. The class was able to quickly freeze some everyday objects, such as flowers, rubber bands, rubber ducks and bananas to demonstrate to the students how cold -321 degrees really is.